More Engine Trouble

Just hours after I wrote of Orbital Sciences’ Antares rocket explosion, Virgin Galactica has suffered a similar fate. But this one has claimed at least one human life so far — the pilot — and the co-pilot is in bad shape.

SpaceShipTwo apparently suffered an engine explosion moments after ignition, and after it was dropped from the WhiteKnightTwo mothership. This was the first in-flight explosion for the system, but there is a history here.

SpaceShipOne, GovernmentZero

Around 2000, Burt Rutan’s Scaled Composites company began development of private vehicle that could reach the edge of space, 100,000 kilometers or 328,000 feet. Call it 62 miles up. He’d been noodling this idea for six years, and by then had laid out the requirements and concepts.

To accomplish the mission, he needed a unique configuration (spacecraft and carrier craft), a unique design (wings that fold up to act as high-drag surfaces for re-entry), and a unique engine (a non-toxic, liquid nitrous-oxide/rubber-fuel hybrid system).
SpaceShipOne design
It all worked well, ultimately, and after many gliding and powered test flights, SpaceShipOne became in 2004 the first privately funded manned vehicle to reach space, and did it multiple times. In so doing, Scaled Composites won the Ansari X Prize. As soon as the media became aware of Rutan’s team during the test flights, he became rather hounded by reporters and photographers. And various pundits took shots at his team’s efforts during their early test flights, pouncing upon each component problem. I took the opportunity to send a little note of encouragement borrowing from Rudyard Kipling:

SpaceShipOne

If you can keep your head when all about you
Are losing funding and a future view
If you can trust your team when TV doubts you
But make allowance for the PR crew

If you can wait and plan and run the numbers
And you can keep the funding coming in
And keep the fire while the media slumbers
And run the tests, and tests, and tests again

And you can gather brave and stalwart people
And lead them, and inspire them to heights
If you can give a meaning to the effort
That lights them and keeps them awake for nights

If you can overcome the normal glitches
As when a microswitch gets stuck and fries
And even when those grab you by the britches
As from that switch, a pilot almost dies

And you can keep the business side together
Rememb’ring that the cash flow must go on
And you can wait for days for sunny weather
Remaining calm and still as winter dawn

If you can dream, beyond what most are trying
If you can think, and put the thought to use
If you can overcome equipment dying
And you can rise above the world’s abuse

The X-Prize beckons you to come and win it
If your resolve’s as strong as when begun
Then yours is space and everything that’s in it
And you can claim that prize … with SpaceShipOne

Change of fuel

The success of SpaceShipOne brought immediate benefits, including funding from Sir Richard Branson (creating a new Virgin spinoff called Virgin Galactic) and along the way an absorption of Scaled Composites by Northrup Grumman.

Thus, not long after the X Prize win in 2004, the team began work on SpaceShipTwo, a larger, five-paying-passenger craft that needed a larger mothership to get it to launch altitude. The design they came up with for the mothership was strikingly similar to an old Soviet design, which I noted at the time.

But before this unveiling, Rutan’s team had also been hard at work on a new, more powerful engine for the larger SpaceShipTwo. This was done for a while outside of the media spotlight, but they were thrust upon the world stage again in 2007 when tragedy struck: An engine on a test stand exploded, killing several key team members.

This horrific incident occurred just days after Rutan had inked a deal for Branson’s stake to go from 40% to 100%, accompanied by major additional funding. For a while, not much was heard from them … then news came out that Rutan’s team was back at work on a new engine with a new fuel.

Back to the drawing board

The team decided to change the fuel used for the engine, to a rubber-based HTPB solid fuel. This was a major redesign, but there were no further explosions in the news and the very public rollout of WhiteNightTwo and SpaceShipTwo gave the world confidence again.

But along the way, Burt Rutan retired from this project.

For nearly seven years, SpaceShipTwo has been inching along, with a careful series of test flights. But in May, 2014 came a surprise: The fuel was being changed again, this time to a thermoplastic polyamide (something like nylon) as the solid fuel. Apparently, the engine had suffered “instability” using the prior fuel for burns longer than twenty seconds, and so they needed a redesign again.

It was that new motor and fuel in SpaceShipTwo when it exploded today, in what is reputed to be the first powered flight with this new system. My heartfelt condolences go to the families and the team members.

Not Done Yet

As an aside, Burt Rutan is not exactly compleytely retired. A new group of partners (including Orbital Sciences) has been quietly assembling a new way to reach orbit: Stratolaunch:

===|==============/ Keith DeHavelle

Categories